Stability of a vacuum nonsingular black hole

This is the first of series of papers in which we investigate stability of the spherically symmetric space-time with de Sitter center. Geometry, asymptotically Schwarzschild for large $r$ and asymptotically de Sitter as $r\to 0$, describes a vacuum nonsingular black hole for $m\geq m_{cr}$ and particle-like self-gravitating structure for $m < m_{cr}$ where a critical value $m_{cr}$ depends on the scale of the symmetry restoration to de Sitter group in the origin. In this paper we address the question of stability of a vacuum non-singular black hole with de Sitter center to external perturbations. We specify first two types of geometries with and without changes of topology. Then we derive the general equations for an arbitrary density profile and show that in the whole range of the mass parameter $m$ objects described by geometries with de Sitter center remain stable under axial perturbations. In the case of the polar perturbations we find criteria of stability and study in detail the case of the density profile $\rho(r)=\rho_0 e^{-r^3/r_0^2 r_g}$ where $\rho_0$ is the density of de Sitter vacuum at the center, $r_0$ is de Sitter radius and $r_g$ is the Schwarzschild radius.Comment: 18 pages, 8 figures, submitted to "Classical and Quantum Gravity

Realization and Properties of Biochemical-Computing Biocatalytic XOR Gate Based on Enzyme Inhibition by a Substrate

We consider a realization of the XOR logic gate in a process biocatalyzed by an enzyme (here horseradish peroxidase: HRP), the function of which can be inhibited by a substrate (hydrogen peroxide for HRP), when the latter is inputted at large enough concentrations. A model is developed for describing such systems in an approach suitable for evaluation of the analog noise amplification properties of the gate. The obtained data are fitted for gate quality evaluation within the developed model, and we discuss aspects of devising XOR gates for functioning in "biocomputing" systems utilizing biomolecules for information processing

Estimation of fossil-fuel CO2 emissions using satellite measurements of &quot;proxy&quot; species

International audienceFossil-fuel (FF) burning releases carbon dioxide (CO 2) together with many other chemical species, some of which, such as nitrogen dioxide (NO 2) and carbon monoxide (CO), are routinely monitored from space. This study examines the feasibility of estimation of FF CO 2 emissions from large industrial regions by using NO 2 and CO column retrievals from satellite measurements in combination with simulations by a mesoscale chemistry transport model (CTM). To this end, an inverse modeling method is developed that allows estimating FF CO 2 emissions from different sectors of the economy, as well as the total CO 2 emissions, in a given region. The key steps of the method are (1) inferring "top-down" estimates of the regional budget of anthropogenic NO x and CO emissions from satellite measurements of proxy species (NO 2 and CO in the case considered) without using formal a priori constraints on these budgets, (2) the application of emission factors (the NO x-to-CO 2 and CO-to-CO 2 emission ratios in each sector) that relate FF CO 2 emissions to the proxy species emissions and are evaluated by using data of "bottom-up" emission inventories , and (3) cross-validation and optimal combination of the estimates of CO 2 emission budgets derived from measurements of the different proxy species. Uncertainties in the top-down estimates of the NO x and CO emissions are evaluated and systematic differences between the measured and simulated data are taken into account by using original robust techniques validated with synthetic data. To examine the potential of the method, it was applied to the budget of emissions for a western European region including 12 countries by using NO 2 and CO column amounts retrieved from, respectively, the OMI and IASI satellite measurements and simulated by the CHIMERE mesoscale CTM, along with the emission conversion factors based on the EDGAR v4.2 emission inventory. The analysis was focused on evaluation of the uncertainty levels for the top-down NO x and CO emission estimates and "hybrid" estimates (that is, those based on both atmospheric measurements of a given proxy species and respective bottom-up emission inventory data) of FF CO 2 emissions, as well as on examining consistency between the FF NO 2 emission estimates derived from measurements of the different proxy species. It is found that NO 2 measurements can provide much stronger constraints to the total annual FF CO 2 emissions in the study region than CO measurements , the accuracy of the NO 2-measurement-based CO 2 emission estimate being mostly limited by the uncertainty in the top-down NO x emission estimate. Nonetheless, CO measurements are also found to be useful as they provide additional constraints to CO 2 emissions and enable evaluation of the hybrid FF CO 2 emission estimates obtained from NO 2 measurements. Our most reliable estimate for the total annual FF CO 2 emissions in the study region in 2008 (2.71 ± 0.30 Pg CO 2) is found to be about 11 and 5 % lower than the respective estimates based on the EDGAR v.4.2 (3.03 Pg CO 2) and CDIAC (2.86 Pg CO 2) emission inventories , with the difference between our estimate and the CDIAC inventory data not being statistically significant. In general, the results of this study indicate that the proposed method has the potential to become a useful tool for identification of pos-Published by Copernicus Publications on behalf of the European Geosciences Union. 13510 I. B. Konovalov et al.: Estimation of fossil-fuel CO 2 emissions sible biases and/or inconsistencies in the bottom-up emission inventory data regarding CO 2 , NO x , and CO emissions from fossil-fuel burning in different regions of the world

Design, Spectral Characteristics, Photostability, and Possibilities for Practical Application of BODIPY FL-Labeled Thioterpenoid

This paper presents the design and a comparative analysis of the structural and solvation factors on the spectral and biological properties of the BODIPY biomarker with a thioterpene fragment. Covalent binding of the thioterpene moiety to the butanoic acid residue of meso-substituted BODIPY was carried out to find out the membranotropic effect of conjugate to erythrocytes, and to assess the possibilities of its practical application in bioimaging. The molecular structure of the conjugate was confirmed via X-ray, UV/vis-, NMR-, and MS-spectra. It was found that dye demonstrates high photostability and high fluorescence quantum yield (to ~100%) at 514&ndash;519 nm. In addition, the marker was shown to effectively penetrate the erythrocytes membrane in the absence of erythrotoxicity. The conjugation of BODIPY with thioterpenoid is an excellent way to increase affinity dyes to biostructures, including blood components